Re: my vibrate doesn't work

Have you tried a simple battery pull? While the device is on, remove the battery for 15-30 seconds, reinsert and wait for the device to reboot. This often works for these sorts of issues.

If that doesn't work, the next step is to ensure that your notifications are indeed supposed to vibrate according to your settings. Go to Sounds and then change the sounds associated with your active profile. Make sure that things like Phone Calls, Messages, etc are set to vibrate as desired.

The next step would be to see if its a software issue. In this case, you would want to reload the software on the device using the method described here: